The purpose of the Virology Core, located at the Aaron Diamond AIDS Research Center, is to provide HIV virology support to researchers in the NYU CFAR. Several virologic tests are offered routinely, including HIV isolation, p24 antigen assay, diagnostic PCR, HIV quantitation by culture and PCR, determination of plasma viremia by the branched-chain DNA amplification method, and phenotyping of patient viruses. Additional HIV tests are performed by special arrangement, including HIV propagation and titration, drug sensitivity testing, antibody neutralization of laboratory strains or field isolates, reverse transcriptase assays, and PCR-based nucleotide sequencing. Heteroduplex mobility shift assay, ELISA's to measure CD4-gp120 binding, epitope mapping of antibodies, and several in situ techniques are also in the repertoire of the Virology Core. These techniques and our overall expertise on HIV virology will be utilized to enhance the research activities in the NYU CFAR, particularly in the areas of pathogenesis, transmission, and vaccine research.